The present invention relates to an apparatus for separating the gaseous hydrogen isotopes protium, deuterium and tritium from a gas or gas mixture containing one or a plurality of the hydrogen isotopes.
The separation of hydrogen isotopes from gas mixtures is necessary, in particular, in coolant circuits of gas cooled high temperature reactors and in fuel circuits of fusion reactors. In addition to their separation, the recovery of the hydrogen isotopes for their further use is also of significance.
An apparatus is disclosed in DE-OS No. 2,854,682 for separating hydrogen isotopes from a gas mixture wherein a membrane wall is provided which is permeable for hydrogen isotopes. The apparatus comprises an inner chamber and an outer chamber separated from one another by a wall which is preferably permeable for atomic hydrogen and only slightly permeable for molecular hydrogen. One chamber is connected with a gas inlet line for the hydrogen isotope mixture which is to be separated and with a gas discharge line. The other chamber collects the isotope mixture which passes through the permeable wall. A device for converting molecular hydrogen to atomic hydrogen is disposed in the chamber connected with the gas inlet and gas discharge lines so as to separate the isotopes contained in the hydrogen isotope mixture.
Furthermore, DE-OS No. 2,449,553 and corresponding U.S. Pat. No. 3,969,185, disclose a composite getter which essentially includes as the getter material zirconium or zirconium alloys with niobium, titanium, nickel and yttrium. The composite getter can be used to getter hydrogen and its isotopes. The composite getter is comprised of a metallic substrate having thereon a coating of a material capable of gettering reactive gases covering at least a portion of the substrate, with the substrate having a greater thermal coefficient of expansion than the coating and being capable of producing tensile stress in the coating whereby the coating is intermittently fractured by changes in temperature of the composite getter to thereby expose fresh gettering surfaces in the coating.